The present invention relates to a chair, in particular an office chair, comprising a base structure, a seat support structure articulated to the base around a transverse axis and an adjustable elastic device to apply an elastic force between a base structure and the seat support structure.
Traditional office chairs are usually provided with a compressed spring positioned between the base structure and the seat support structure. Normally, an adjusting device is provided which allows the user to adjust the compression pre-load of the spring to vary the elastic reaction force according to his/her needs. One of the main drawbacks of traditional solutions is that said adjusting device is usually located underneath the seat, in a position that is difficult to reach by the user. Moreover, known adjusting devices require a large actuating force, which makes the adjustment operation difficult. The actuating force the user must manually apply to the adjusting device is not constant, but grows as the spring pre-load increases.